Method of making cartons



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ATTORNEYS I April 17, 1962 R. w. GRIESE METHOD OF MAKING CARTONS Original Filed May 17, 1957 5 Sheets-Sheet 2 llll xx All Y.

l l I l l ll llll IN VEN TOR. If BER 1- 1446 0 55 ATTORNEYS April 17, 1962' R. w. GRIESE METHOD OF MAKING CARTONS Original Filed May 17, 1957 5 Sheets-Sheet 3 Hg 6 I3 300 c l2\/ /g. 7 l3 y '4 I a b 11 Fig. 8 5

IN VEN TOR. finds/e1- h 6 8/55 ATTORNEYS ilite Estes atent dice 3,029,711 Patented Apr. 17, 1962 2 Claims. or. 93-66) packaged 'therein.

This application is a division of application Serial No. 659,918, filed May 17, 1957.

will at the same time become adhered to glue area .26 on panel 15. Adhesive is then applied to "glue 'panel 16 and panel 12 is then folded thereon as shown in FIG- Further details and advantages of the invention will ing a carton therefrom,

FIGURE 5 is a perspective view of a carton formed from the folded and glued blank shown in FIGURE 4, having its upper end open for receiving contents therein to be packaged, I

FIGURE 6 is a sectional view taken on lines 6-6 of FIGURE 5,

"FIGURE 7 is a schematic representation of a crosssection taken on lines 7-7 of FIGURE 4, and 1 FIGURE 8 is a schematic representation similar to FIGURE 6.

Referring to the drawings, the carton preferably is made from a single blank of suitable flexible sheet material, such as cardboard, metal foil, plastic sheet mater'ials, and the like of desired thickness and dimensions. The blank is suitably scored along lines indicated by numerals 1 to 8, and cut along lines 9, 10 and 11, as shown in FIGURE 1 to provide end walls or panels 12 and 14, side walls or panels 13 and 15, respectively, and end flaps 17, 19,. 20 and 21 hinged to the aforementioned walls 12 to respectively. The respective panels are adapted to be positioned in substantially parallel relationship, as shown in FIGURE '5 in the completed setup carton. The respective pairs of walls are also preferably of substantially the same dimensions. Glue panel 16 is adapted to be adhered to overlapped portion of end wall 12, as shown in FIGURE 6 to provide a tubular carton of rectangular cross-section.

In forming a carton from the blank shown in FIGURE 1 and simultaneously providing a fiexible strut or bridge within the carton, the following procedure may be carried out. Glue areas 25 and 26' of suitable area and dimensions are applied to panels 13 and 15, as shown in FIGURE 1. These glue areas are preferably positioned at approximately the medial portions of panels 13 and 15. A flexible strip 30, made of suitable material, such as paper, cellophane, glassine, and the like of suitable dimensions is then positioned on panel 13 and one end 25 thereof is adhered to the glue area 25'. Panel 15 is then folded along score line 3 so as to overlie panel 13, as shown in FIGURE 3. The end 26 of strip 30 URE 4. The glued blank'is then set up and the'bottom closure is formed by folding flaps '17 andZt) inwardly, folding flap 1'9 thereover, and then folding. over flap '21 and adhering same to the flaps underneath in anysuitable manner.

Theresulting structure is shownin FIGURE 5,1the inner flexible strip 30 extending between side walls 13 and 15. Astpreviously indicated, this invention involves a carton with opposed pairs of parallel side walls, and the walls of one pair are intended to be'p'e'rpendicular to the other pair. Under such'con'ditions, it is clear that in the usual case it will be desirable for maximum oftectiveness to locate the strut'in 'themid'portio'n of*the carton, or perhaps slightly below in order to account for settling of the contained product. However, the strut of course may be located at. any desired part of the carton. In the usual situation, it alsowill be desirable to locate the strut perpendicular tothe walls to'which it is attached and of length equal to the spacing between these walls along their lateral edges. However,..by adjusting the location of glue areas 25' and 26', and coordinating the effective unadhered length 30a of strut .30' therewith, the strut may be accommodated to either pull the side walls of the carton inwardly or to let the side wallsbulge outwardly, as will be described later.

After the carton is filled with any suitable commodity to be packaged therein the end'flaps 17 and 20 are folded inwardly and the closure flaps 1 9 and 21 are folded over and suitably-adhered to seal the. carton. The flexible strut 30 within the carton will. prevent the opposed walls 13 and 15 of the carton from bulging outwardly,.especially when dense or heavy materials are packaged in the cartons. When cartons of fairly large size are used, such as for packaging supersize granulated detergents, which may have parallel front and rear panels measuring say 10 x 16 inches, there is a pronounced tendency for these panels to bulge outwardly and thus ,present an unsightly appearance. The provision of an internal flexible strut or bridge in accordance with this invention will prevent such undesirable bulging and will maintain the package in proper shape without bulging walls.

The carton provided with the internal strut may be made with any suitable equipment. Another method of forming the carton, usinga similar blank as shown in FIGURE 1, can be followed by first prebraking score line 4 on which glue .flap 16 is hinged. Adhesive is then applied to areas 25' and 26. One end of flexible .rut strip 30 is then attached to glue area 26. Score line 3 is prebroken and adhesive is applied to the reverse face of glue flap 16' as shown in FIGURE 1. Panel 15 is then folded over on panel 13. Panel 12 is then folded over one glue panel 16 whereby the glued blank'as shown in FIGURE 4 is produced.

FIGURE 7 is a schematic cross-section of the carton in the condition shown in FIGURE-4, the 'unadhered portion 39a of stnut 30being hinged to the side walls at x and y. Hinge lines at and ylare respectively spaced from end wall 14 by distances a and c, and the side and end walls are respectively of dimensions "d a'ud b. FIG- UR'E'7 shows the carton extendedslightly toward the strut 30, its length in the carton-erected position of FIGURE 5 will be precisely equal to the lateral dimension of end walls 12 and 14, and the strut will assist in maintenance of a carton of parallelogram cross-section.

It is also clear that if glue areas 25' and 26 are located so that in forming the carton (FIGURE 7) a distance a is greater than distance 0, the strut will be of length greater than the distance between x and y in the rectangular formation of the carton as shown in FIG- URE 5, and the strut will permit the carton to bulge beyond a rectangular cross-section Conversely, if the distance a is less than distance c, stnut 30a in erected condition will be of length less than the lateral dimension of the end walls and the strut will consequently pull the side walls inwardly when the carton is erected.

Applicant has discovered that there are certain limitations on the positioning of the glue areas 25' and 26. Referring also to FIGURE 8, it is apparent that the lateral displacement e between hinge lines x and y must, in the carton-erected condition, never exceed the length of strut 30. This conclusion results from the fact that the strut must span the combination of the displacement e and the displacement between the hinge lines perpendicular to e, so clearly e alone can never equal the length of the strut.

elength of strut 30 5 means equal. to or less than Length of strut'30=a+bc (see FIGURE 7) From which,

2 means equal to or greater than It is also clear that the tendency of the carton to distort to accommodate its contents necessarily ends at the point where the maximum capacity of the carton is reached. This would occur when the cross-section of the carton became circular. Thus, so long as strut 30 is of length no greater than the diameter of such a circle, theoretically it may be of value in restricting bulging of the carton, although its limit of practical utility would be reached at a much earlier stage. Referring to FIGURE 7, we see that the theoretical limit on length of a useful strut occurs when its length becomes as great as the diameter of a circle the circumference of which is equal to the perimeter of the carton. Thus,

Length of strut 30=a|bc a+bc S diarneter of a circle the circumference of which is 2b+2d It will be clear that in the above description concerning FIGURES 7 and 8, references to strut 30 are intended to mean the efiective connecting (unadhered) portion 30a.

It is to be understood that the invention is not restricted to any specific type of carton construction and that the internal strut or bridge may be suitably applied to any type of carton construction in which the opposed walls may have a tendency to bulge outwardly. It is obvious that the internal strut may be positioned internally of the carton at any suitable location to prevent bulging of the opposed walls and that the dimensions of the flexible strut may be varied depending upon the overall size of the carton. While in most usages the carton must be constructed or" a fairly heavy paperboard or like material, the strut may be formed from a very light paper or film, since it is subject only to tension forces, thus keeping at a minimum the cost of the entire carton. As is clearly illustrated in the drawings, particularly FIG- URES 1 through 5, strut 30 has relatively a very small dimension along the height of the carton, that is, parallel to the longer dimension of walls 12 to 15, so that the strut in no wise forms a partition in or provides a division of the carton, but rather presents essentially no barrier tomovement of contained material from any part of the carton to any other part, regardless of the attitude or degree of fill of the carton. The internal strut should of course have suflicient strength to withstand rupturing upon being stressed by any outward bulging of the carton panels to which is is attached. Also the strut should be adequately adhered over a sufficient area to resist being detached from the surfaces to which it is connected. In some instances the flexible strut may be reinforced with flexible threads or wires. It may also be made of woven textile materials, such as cellulosic films, nylon, Dacron, glass fibers and the like.

. I claim: I

1. The method of manufacturing a reinforced carton shell from a unitary paperboard blank and a reinforcing strip, the blank including a first end wall, first and second side walls along one side edge hinged to the respective opposed side edges of said end wall, a second end wall along one side edge hinged to the other side edge of one of said side walls, and a glue panel hinged to the other side edge of one of said second end wall and the other of said side walls, the method comprising applying glue to a selected intermediate area of each of said side walls, applying one end of said strip to one of said glue areas, thereafter folding the blank along one of the side edges of said first end wall, to cause the other glue area to overlie the other end of said strip and be adhered thereto,

.and applying adhesive along a remote side edge of said blank and folding the blank to bring the glue panel and remote side edge of said second end wall into adhering relationship.

2. The method of manufacturing a reinforced carton shell from a unitary paperboard blank and a reinforcing strip, the blank including a first end wall, first and second side Walls along one side edge hinged to the respective opposed side edges of said end wall, a second end wall along one side edge hinged to the other side edge of one of said side walls, and a glue panel hinged to the other side edge of one of said second end wall and the other of said side walls, the method comprising applying glue to a selected intermediate area of each of said side walls, applying one end of said strip to one of said glue areas, applying adhesive along a remote side edge of said blank, folding the blank along one of the side edges of said first end wall, to cause the other glue area to overlie the other end of said strip and be adhered thereto, and folding the blank to bring the glue panel and remote side edge of said second end wall into adhering relationship.

References Cited in the file of this patent UNITED STATES PATENTS 

